Abstract:
Amongst the man made ionizing radiations, X - ray diagnostic procedures contribute
the highest per capita radiation dose to population over and above the natural
background radiation. Although the X-ray diagnostic procedures have revolutionized
medical diagnosis and treatment of many diseases, their extensive use has raised
concern on possible over exposure. The patient may receive radiation dose in excess
due to bad practice and bad equipment and hence every X-ray machine should be
subjected to periodic quality assurance (QA) tests. Poor functioning of any parameter
may lead to retake of X-ray, which in turn increases cost and radiation to patient and
staff. Moreover the knowledge of radiation doses received by the patients during
radiological procedure is necessary and all efforts must be made to keep the radiation
dose to minimum level. The aim of this work was to determine the current status of
diagnostic X-ray machines used in medical facilities in the western region of Kenya. In
this study, we present the findings from quality control of general radiographic X-ray
equipment in 31 medical facilities in western Kenya during 2009 and early 2010,
including mobile X-ray units and film/screen fixed systems. The facilities were
assessed by means of a visual checklist thereafter one functional X-ray machine per
facility was subjected to QC tests since 90% of the facilities visited had only one X-ray
machine being used. Four QC tests were performed on 15 X-ray machines. These were
beam alignment and perpendicularity tests, kVp accuracy and reproducibility tests,
exposure time accuracy and reproducibility tests and filtration tests. Beam alignment
and perpendicularity tests showed unacceptable variation in 40% and 47% respectively
while kVp accuracy test showed unacceptable variation in 27%. The study also showed
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clearly the high rate of increase of the number of X-ray machines in the region. The
facilities had a total of 52 X-ray machines of which 38.5% were functional, 42.3% were
working with defects and 19.2% were out of order.
